4 in lb psi 1 300 932 180000 000398 2 300 862 209000

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4in.- lb psi. 1 .300 93.2 180,000 .000398 _________ _________ 2 .300 86.2 209,000 .000398 _________ _________ 3 .300 77.6 900,000 .000398 _________ _________ 4 .300 76.6 3,000,000 .000398 _________ _________ 5 .300 76.3 9,000,000 .000398 _________ _________ *6 .300 76.0 10,000,000 .000398 _________ _________ Data For NOTCHEDSpecimen (Static Ultimate = 120 ksi)- See Figure 1 for geometry pertinent to the calculations below: Spec. Dia. at Load P No. of cycles I=Moment M=Total Max Stress No. Center lb. (N) for Failure of inertia Moment =Mc/I in.4in.- lb psi. 1 .300 61.7 108,000 .000398 _________ _________ 2 .300 59,0 131,000 .000398 _________ _________ 3 .300 56.4 160,000 .000398 _________ _________ 4 .300 54.7 1,400,000 .000398 _________ _________ 5 .300 54.4 9,500,000 .000398 _________ _________ *6 .300 54.1 10,000,000 .000398 _________ _________ *Specimen did not fail
72 Data For MILD STEEL Specimen (Static Ultimate = 52.6 ksi)- See Figure 2 for geometry pertinent to the calculations below: Spec. Thick- Width I=Moment P M=Total Max Stress N No. ness “t” “w” of inertia lb. Moment =Mc/I (103) in. in. 10-5 in.4in.-LB psi. 1 .066 1.492 ____________ 108.0 ____________ ____________ 15 2 .064 1.488 ____________ 91.4 ____________ ____________ 55 3 .066 1.480 ____________ 86.1 ____________ ____________ 89 4 .065 1.492 ____________ 73.4 ____________ ____________ 309 5 .064 1.492 ____________ 61.1 ____________ ____________ 1397 6 .064 1.492 ____________ 50.9 ____________ ____________ 76617 .063 1.481 ___________ 48.1 ____________ _____________ 17540 *8 .064 1.479 ____________ 48.5 ____________ _____________ 60120 *Specimen did not fail
73 Experiment 9. Nondestructive Testing Objectives - At the end of this experiment the student will be able to: 1. List at least three forms of nondestructive testing & state briefly how they are performed. 2. Explain the difference between destructive & nondestructive testing. 3. Locate surface cracks or flaws in several specimens provided by means of a liquid penetrant. 4. Locate surface, or near surface, cracks or flaws in several specimens by means of magnetic particle testing. 5. Describe the flaws found. 6. Write and submit a lab report. Background Information Nondestructive testing (NDT) is the examination and testing of an object or material in a manner which does not affect its future usefulness. Nondestructive tests are done to detect internal or external imperfections, to determine structure, composition, or properties, or to measure geometric characteristics - without affecting the form, fit, or function of the test object or material. Nondestructive testing plays an important and essential part in almost all of industry today. There is no such thing as a perfect material. Therefore, in order to meet the rigorous demands placed on many products today NDT is relied upon to assure that the product has the desired specified characteristic properties. Some of the more common types of NDT are briefly described below: RADIOGRAPHY - Radiography involves the use of penetrating x or gamma radiation to examine parts and products for imperfections. An x-ray machine or radioactive isotope is used as a source of radiation. Radiation is directed through a part and onto film. When the film is developed, a shadowgraph is obtained that shows the internal soundness of a part. Possible imperfections show up as density changes in the film, in much the same manner as an x-ray can show broken bones. MAGNETIC PARTICLE - Magnetic particle testing is done by inducing a magnetic field in a ferromagnetic material and dusting the surface with iron particles (either dry or suspended in a liquid). Surface imperfections will distort the magnetic field and concentrate the iron particles near imperfections, thus indicating their presence.

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